The detection of dementia and cognitive impairment in a community population of elderly people with Parkinson's disease by use of the CAMCOG neuropsychological test

Aim: to assess cognitive function in elderly subjects with clinically proba ble Parkinson's disease (PD). Methods: a community sample of 126 patients with probable PD completed the CAMCOG, which is the cognitive section of the Cambridge Examination for Men tal Disorders, and the Mini-Mental State Examination (MMSE). The performanc e of the CAMCOG and the MMSE in detecting dementia in this subject group wa s compared with the results of applying the DSM-IV criteria for dementia to this population. Results: A total of 44% of the group met DSM-TV criteria for dementia, whic h is higher than most previous prevalence figures for dementia in PD. The C AMCOG was more sensitive than the MMSE in detecting cognitive impairment an d more specific than the MMSE in detecting dementia as defined by DSM-Til c riteria. Poorer performance on the CAMCOG was related to gender, social cla ss and age (P < 0.05). Among subjects with PD, those with dementia, as defi ned by DSM-IV criteria, were significantly older, had greater depressive sy mptomatology and had greater motor deficits. A greater proportion of the gr oup with dementia were living in residential care (P < 0.05). Conclusion: The CAMCOG appears to be a useful screening instrument for deme ntia and cognitive impairment in PD. Furthermore, it may prove helpful in d etecting those with PD who may be at risk of developing dementia and in lon gitudinal studies of cognitive function in PD.